A stone is allowed to fall down from the top of a tower 100m high and at the same time another stone is projected vertically upwards from the ground with a velocity of 25 ms^{-1}. Calculate when and where the two stones will meet? (take g = 10ms^{-2})

Let a stone A is allowed to fall from top of a height h = 100m

Its initial velocity u_{1} = 0

And a_{1} = +g = +10 ms^{-2}

Another stone B is projected upwards from the ground with an initial velocity u_{2} = 25ms^{-1} and for it a_{2} = -g = -10 ms^{-2}

Let the two stones meet at a point C at a distance y below A or (100-y) above B after a time t.

Then for stone A

For stone B